Cognitive and behavioral functioning in Coffin-Siris syndrome and epilepsy: a case presentation.

The authors characterized the cognitive, adaptive, and behavioral sequelae of Coffin-Siris (CS) syndrome and epilepsy in a 7.5-year-old child. Little is known about the early neurobehavioral presentation of CS. Clinical features consistent with this genetic anomaly include underdeveloped tips and nails of the fifth fingers, extended infranasal depression, and craniofacial abnormalities. MRI findings often reveal callosal agenesis. The authors conducted a neuropsychological evaluation and obtained parental ratings of behavioral and adaptive functioning. Attentional abilities were limited. As assessed by the Mullen Scales of Early Learning, receptive language abilities (age equivalent [AE]: 3-3) were relatively stronger than expressive skills (AE: 1-4). Adaptive functioning was low across all domains (Vineland Adaptive Behavior Composite AE: 1-9). On the Behavior Assessment for Children (BASC-2), social skills dysfunction, stereotyped and self-stimulatory behaviors, restricted interests, ritualistic play, and inappropriate object usage were noted. No significant mood disturbances were endorsed. Study findings indicate a diffuse pattern of neurobehavioral deficits in a child with CS and epilepsy. Further clinical assessment and research should include multidimensional assessment techniques, including evaluation of adaptive behavior, in an effort to capture the full range developmental sequelae in children with CS.

Language lateralization in individuals with callosal agenesis: an fMRI study.

Since the seminal work of Broca in 1861, it is well established that language is essentially processed in the left hemisphere. However, the origin of hemispheric specialization remains controversial. Some authors posit that language lateralization is genetically determined, while others have suggested that hemispheric specialization develops with age. Tenants of the latter view have further suggested that the adult pattern of left hemispheric specialization is achieved by means of callosal inhibition of homologous speech areas in the right hemisphere during ontogeny. According to this hypothesis, one would expect language to develop bilaterally in the acallosal brain. A recent functional magnetic resonance imaging (fMRI) study in one patient with agenesis of the corpus callosum suggests that this might indeed be the case (Riecker et al., 2007). However, given the large anatomic and functional variability in the population of subjects with agenesis of the corpus callosum, this finding needs to be more extensively replicated. In the present study, we explored language lateralization in six individuals with agenesis of the corpus callosum using an fMRI protocol which included a syntactic decision task and a sub-vocal verbal fluency task. Two neurologically intact control groups, one comparable to the acallosals in terms of IQ, age and education (n=6) and one group with a high IQ (n=5), performed the same tasks. No differences were found between language lateralization of the subjects with agenesis of the corpus callosum and the control groups in the receptive speech task. However, for expressive speech, the groups differed with respect to frontal activations, with the acallosal participants showing a more bilateral pattern of activation than the high-IQ participants only. No differences were found for temporal regions. Overall, these results indicate that the corpus callosum is not essential for the establishment of lateralized language functions.

Neurological and psychiatric aspects of corpus callosum genesis.

This article reports the case of a patient with partial agenesis of the corpus callosum manifested with corpus callosum syndrome together with signs of brain hemispheres dysfunction: mental impairment, epilepsy and pyramidal signs. The patient's malformation is combined with left-handedness while signs of callosal disconnection are not present. Mild cognitive impairment and late epilepsy onset require a multidisciplinary approach since the patient also displays elements of central nervous system malformations.

[Von Economo neurons and insular cortex - the bridge between soma and psyche]. / Von Economo und Inselrinde - Brücke von Soma und Psyche.

New research suggests a pivotal role of the anterior insular cortex for the integration of somatic sensation and for intuitive decisions in complex social situations. Functional magnetic resonance imaging (fMRI) has demonstrated a close coupling between the anterior insular cortex and the anterior cingulate gyrus, the only areas with von Economo-neurons. These large spindle cells are exclusively found in species with complex social lifes (apes, cetaceans). Observations in humans showed decreased numbers of von Economo neurons in patients with frontotemporal dementia, or agenesis of the corpus callosum, conditions with impaired theory of mind and interpersonal behaviour. It almost appears as if spindle cells would reach out from the realm of subconscious gut-feelings into the premises of conscious prefrontal planning.

Social narratives in agenesis of the corpus callosum: linguistic analysis of the Thematic Apperception Test.

In a previous study, individuals with agenesis of the corpus callosum (ACC) with normal intelligence provided narratives to pictures from the Thematic Apperception Test (TAT) that were limited in logical coherence and social awareness. The current study examined the linguistic content of TAT stories from 22 persons with isolated complete ACC compared to 30 IQ- and age-matched controls using the Linguistic Inquiry and Word Count (Pennebaker et al., 2001). Compared to controls, individuals with ACC used fewer words pertaining to emotionality, cognitive processes, and social processes. They also used relatively more present tense verbs and first person pronouns. These findings suggest that callosal agenesis results in deficiencies in imagining and inferring the mental, emotional, and social functioning of others as implied by TAT pictures, and in translating this content into a narrative. In addition, ACC affects the grammatical structure of verbally produced narratives, with greater emphasis on the present tense and the first person.

Interhemispheric transfer of kinesthetic information and line bisection task performance in patient with callosal agenesis.

Patient G.J., male, 7 yrs, with callosal agenesis, was found perfectly able to cross-replicate hand postures in right-to left and left-to-right directions. Bimanual coordination as well as touch localization and intermanual matching were performed without errors. He failed to name 2 out of 8 objects, palpated with the left hand. At the age of 13 patient performed like normal controls in line bisection task, was successful in intermanual replication of hand postures and intermanual matching while failed to name 8 out of 12 familiar objects palpated with the left hand. G.J.'s case does not support idea about bilateral presentation of language centers and development of compensatory ipsilateral afferents in patients with callosal agenesis. Presence of anterior and interictal commissures in G.J. did not contribute to the exchange of information between sensory areas of the right hemisphere and language centers of the left half brain. However, normal intermanual matching and replication of hand postures, as well as high level of line bisection task performance suggests, that anterior and/or intertectal commissure could contribute to the functional integration of sensory areas of the two hemispheres.